ایران از جمله کشورهای کم آب جهان می باشد مدیرت منابع آب موجود از مهم ترین مسائل مهندسی آب می باشد. بخشی از آب موجود در سطح و زیر زمین با فلزات سنگین ادغام شده و از کیفیت آنها کاسته می شود. در این مقاله به بررسی کیفیت منابع آب دشت گرمسار پرداخته می شود. داده های مورد نیاز به صورت میدانی از چاه ها و خاک منطقه دریافت گردیده است و جهت مدلسازی از نرم افزار GMS استفاده شده است. در ادامه جهت بهبود شرایط موجود راهکاری ارائه شده است و نتیجه آن با وضع موجود مقایسه گردیده است. نتایج نشان داد که سناریو 2 بیشترین تاثیر را بر روی کاهش مقادیر فلزات سنگین داشته است و از طرفی سناریو شماره 4 دارای کمترین تاثیر بر روی مقادیر بوده است.در صورت بکارگیری راهکار از میزان فلزات سنگین در آب دشت گرمسار کاسته می شود. تفاصيل المقالة

گوگرد به صورت معدنی و آلی در زغال سنگها وجود دارد و یکی از مهمترین عناصر مزاحم در صنعت فولاد سازی است . بالا بودن درصد گوگرد موجود در زغال سنگهای طبس به عنوان یک عنصر آلاینده و مضر مطرح می باشد. گوگرد علاوه بر کاهش راندمان تولید در کارخانه های کک سازی ، باعث آلودگی محیط زیست می گردد. بررسی کاهش میزان گوگود به روشهای فیزیکی مانند شناور ساز یکی از اهداف این نوشتار ا ست. بررسی نمونه های زغالی در روش شناور سازی و فاکتور های موثر درافزایش راندمان جداسازی گوگرد مورد بررسی قرار می گیرد . عواملی همچون میزان خاکستر ،تاثیرکلکتورها و کف سازه ها و وی‍ژگیهای مکانیکی و شرایط سلولهای شناور سازی مد نظر قرار دارد. مقدار کلکتور و مقدار کف کننده و درصد پالپ و زمان ماند متغیرهایی هستند که در زمینه کاهش گوگرد زغال سنگ در روش فلوتاسیون موثر می باشند.با افزایش مقدار کلکتور نفت سفید، مقدار بازیافت و میزان کاهش گوگرد پیریتی با یک روند آرام افزایش می یابد. افزایش یا کاهش بیش از حد دور موتور، میزان گوگردزدایی را کم می کند. افزایش درصد پالپ بر روی کاهش گوگرد و کاهش خاکستر درصد بازیافت را افزایش می دهد. تفاصيل المقالة

Eroded sediments from catchment areas transport by streams and deposit in downstream less steep areas. Despite reducing the useful life of various hydraulic structures including reservoir dams, flood walls, and bridges, this phenomenon changes the main river hydraulic conditions and increases the flood prone farms in the riverbank area. Check dams are among the structures that can prevent form such phenomenon. In addition to the technical performance, hydraulic structures including dams can provide beautiful view in the areas that have the potential to attract tourists. Stepped Slit Check Dams are combination of stepped and slit check dams. The present study investigated the effects of slope, discharge, gradation type, and check dam geometry on the sediment-trapping coefficient of the dam. Finally, a relation for prediction of the sediment-trapping coefficient in the reservoir of Stepped Slit check dams was presented. تفاصيل المقالة

Check dams are one of the structures used to control debris flows. In this study, in order to evaluate the effect of hydraulic parameters on debris sediment trapping rate by the slit trapezoidal check dams with different angles, and to develop an empirical relation for determination of trapping coefficient of the dam reservoirs, three physical models of the check dams were used. The tests were performed on a shapeable flume with 15, 20 and 25 ° slopes, under 20, 25 and 30 liters per minute flow rates, 60, 75 and 90 degrees of check dam angles to the horizontal and for a sediment aggregate with a non-uniform gradation. By determination of the effective dimensionless parameters, the effect of these parameters on debris sediment trapping rate was evaluated by plotting diagrams. The analysis of experiments showed that, the trapping rate of the check dam increased by decreasing the channel slope, increasing the check dam spillway height and decreasing the check dam angle. Different relations were evaluated using linear and non-linear multivariate correlation analyses of dimensionless parameters, and a multivariate relation for determination of the sediment trapping coefficient was proposed. تفاصيل المقالة

According to the water resources and climate change and challenges of Urmia Lake basin, which is the discharge and final destination of North West Rivers, a model was presented. Due to climate change and water resources in river basin such as rainfall, climate change in basin that has direct impact on evaporation over water catchment areas and lake water, this model can be provided. In addition, the inflow to the lake and the lake water-level fluctuations with the high accuracy and acceptable to experts could be estimated by this modeling and the lake water-level is going to be predicted up to one month. In order to simulate monthly fluctuations of the Lake water-level, this paper dealt with modeling the lake water level using two methods, Water Balance Equation and Local LinearNeuro-Fuzzy Network. In this study, to evaluate models’ accuracy, all of them were assessed by three most famous criteria including Root Mean Squares Error (RMSE), correlation coefficient (R), and similarity. The results obtained by Local LinearNeuro-Fuzzy Network modeling indicated that the concomitant use of cumulative flow (entering the lake), monthly precipitation and monthly evaporation on the lake surface provided the best performance with high accuracy regarding the simulated fluctuations of the monthly water level in Urmia Lake. تفاصيل المقالة

The present study examined the effect of the geometric parameters of the Rockfill dams on the 2D static analysis of slope stability. In this regard, several numerical models analyzed for eight heights, three slopes of upstream and downstream, three vertical and skewed core thicknesses and four different impounding time stages namely, "End of Construction", "Full Reservoir", "Half Full Reservoir" and "Rapid Drawdown" on a bedrock foundation. The Morgenstern-Price graphical-limit equilibrium method was selected to study the slopes stability. According to the obtained results for all the models and cases, asphaltic concrete core thickness and its inclination had no significant effect on the calculated safety factors of theslope stability. Maximum and minimum stability safety factors obtained for the "Full Reservoir" and "Rapid Drawdown" time stages, respectively. In addition, in terms of upstream and downstream stability safety factors for different types of impoundment, "End of Construction" and "Half Full Reservoir" time stages were rated the second and third, respectively. Based on the final results, stability safety factor of "Half Full Reservoir" must be considered to ensure adequate safety of the dam stability. For the "Full Reservoir" time stage, the upstream safety factor was bigger than the downstream one, whereas for"Half Full Reservoir", the upstream safety factor was smaller than the downstream one in all heights and slopes. تفاصيل المقالة

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